Preparation of hyperbasic dispersions

ABSTRACT

A HYPERBASING PROCESS WHICH COMPRISES: (A)ADMIX SULFONIC ACID, METHANOL, CALCINUM BASE, AND VOLATILE HYDROCARBON SOLVENT; (B) TREAT WITH LESS THAN STOICHIOMETRIC AMOUNT OF CARBON DIOXIDE AT TEMPERATURE NOT OVER 35*C.; (C) ADD NONVOLITE DILUENT OIL; (D) HEAT TO REMOVE ALL VOLATILES; (E) TREAT WITH CARBON DIOXIDE TO CONVERT REMAINING CALCIUM BASE TO CALCIUM CARBONATE; AND (F) FILTER.

PREPARATION OF HYPERBASIC DISPERSIONS Paul C. Kemp, Ponca City, Okla., assignor to -Witco Chemical Corporation, New York, N.Y. No Drawing. Continuation-impart of abandoned applica- 3 tion Ser. No.. 56,010, July 17, 1970. This application Jan. 24, 1972, Ser. No. 220,436 I Int. Cl. C10m 1/40, 3/34 Cl. 25 233.4 18 Claims 1 ABSTRACT OF THE DISCLOSURE hyp'erbasing process which comprises:

(a) admix sulfonic acid, methanol, calcinum base, and ,1 volatile hydrocarbon solvent;

;( b) treat with less than stoichiometric amount of carbon dioxide at temperature not over 35 C.;

,(c) add nonvolatile diluent oil;

(d) heat to remove all volatiles;

e.) treat with carbon dioxide to convert remaining calcium ,base to calcium carbonate; and

CROSS-REFERENCE TO RELATED APPLICATIONS present invention is a continuation-in-part of ap- ..plication Ser. No. 56,010, filed July 17, 1970 and now abandoned. DISCLOSURE Background The use of hyperbasic dispersions as additive agents in lubricating oil compositions is well-known. In general, such f mat'erials serve at least the following functions. First the joilmust possess the ability to disperse insolubles formed "by fpelcombustiop and/or oil oxidation. Secondly, the oil mustbe eapable of neutralizing both the acidic combustion products and acidic lacquer precursors.

' While hyperbasic dispersions containing either barium compounds or calcium compounds are used in lubricating foil com'position's the hyperbasic calcium-containing dispersions are often preferred, primarily because of their JQWCII'JQQSL Moreover, while calcium hydroxide is the dis perjsoid material in many lower base number dispersions in generalcalcium carbonate is the preferred dis- ;persioid material in higher base number dispersions.

Seyera l proc'e ssesare known for preparing hyperbasic dispersions containing calcium carbonate as the dispersoid material. While these processes are satisfactory for preipari'rig .;s'mall batches (cg, 1 liter) of product, it has been my observation that only; a relatively few processes are ,satisfacto'ry forpreparinglarge batches (e.g., at least 100 l of product.

j My invention resides. in the discovery of a process for lpiepari nglhyperbasic, dispersions containing calcium car- ,bonatefwherein the process uses economical materials "1 (e. g'., lime and methanol)" and is satisfactory for preparing jlargebat'ches e.g., 100 gallons and above).

. An 'important feature of'my process is the use of a cerfully controlled amount of carbon dioxide in the carbonation step. This, amount of carbon dioxide, which will itimes' are required to prepare large batches of product, it

is believed'that it is this feature (i.e., amount of carbon a f 'b tches of, product.

;be' described more fully hereinafter, is less than the stoifchiom etric' amount'required to convert the overbasing cal- ;ciurn p'res'ehtjto calcium carbonate. Use of such an amount fof carbon dioxide permits longer heating times in the 2 preparation of. thefp'roduct. Since generally longer heating 3,830,739 Patented Aug. 20, 1974 Moreover, my process provides for a high utilization of lime. By this is meant that a large amount of the lime (CaO or Ca(OH) added is converted to calcium carbonate found in the filtered product. Generally my process provides a lime utilization of at least about more generally at least about Many methods are known for expressing the amount of overbasing metal present in hyperbasic dispersions. The term overbasing" refers to the amount of metal present in excess of that present in the neutral metal salt of the dispersing agent. I prefer to use thebase number method of expressing the amount of overbasing metal present. The term base number refers to mg. KOH per gram of sample. The base number can be either the ASTM base number, which uses an ASTM method, or acetic base number, which term is described in many U.S. and foreign patents (e.g., U.S. 3,150,088). Preferably, the acetic base number is used.

PRIOR ART While many references teach processes for preparing hyperbasic dispersions containing calcium carbonate, U.S. Pat. Nos. 2,865,956 and 3,537,996 are believed to be the most pertinent references to the process described herein. Broadly stated, Pat. No. 2,865,956 teaches the preparation of hyperbasic dispersions containing polyvalent metal carbonates by reacting an oil-soluble polyvalent metal salt of an organic acid (e.g., carboxylic or sulfonic acid), with a polyvalent metal carbonate formed in situ in the reaction mixture.

The patent teaches that C -C alkanols can be used. By contrast, I have found that ethanol and isopropanol do not work in my process. Moreover, the use of methanol requires process conditions outside of those described by U.S. 2,865,956, when methanol is used in the examples of the patent.

U.S. Pat. No. 3,537,996 teaches a process for preparing an overbased calcium hydrocarbon sulfonate. The process comprises contacting an initial admixture of calcium sulfonate, hydrated lime, hydrocarbon lubricating oiland an alcohol selected from the group consisting of alkanols and alkoxy alkanols of from 1-5 carbon atoms, said hydrated lime having a calcium carbonate content of less than 1.5 Weight percent, with carbon dioxide until between about 50 and 83 percent of said hydrated limeis converted to calcium carbonate, clarifying the resulting mixture by means of filtration and recovering said'clarified, overbased calcium sulfonate composition from the filtrate.

The teachings of Pat. No. 3.537.996 are not believed pertinent for the following reasons. The patent teaches that the temperature for blowing with CO should be in the range of -200 F. (54-93 C.) By contrast, the maximum, temperature for the first carbonation step ofmy process is about 35 C. Moreover, the patent teaches that the alcohol can be an alkanol or alk oxy alkanol contaiaing from 1-5 carbon atoms. The process of the -subject application is restricted to the use of methanolfD'atac ontained herein show that the nearest homologs to methanol (ethanol and ispropanol) do network in my process.

: In addition to the foregoing patents thefol-lowingUS. patentsare listed as being concerned with related-art: 3,027,325; 3,057,896; 3,312,618; 3,470,097;-23,488,284; 3,492,231. Inasmuch as these references arebelieved, be less pertinent than those discussed in the ,foregoing, notconsidered necessary to discuss them: herein.--'

BRIEF sUMMARYf'oF THE INvENTICSri 85 mole.

bonate in a nonvolatile diluent oil, wherein the process comprises:

(A) forming an admixture of (1) oil-soluble dispersing agent (2) volatile hydrocarbon solvent (3) methanol (4) calcium oxide or calcium hydroxide in an amount to provide the desired base number.

(B) treating the admixture of step (A) with a carefully controlled amount of carbon dioxide while controlling the temperature of the reaction admixture,

(C) adding nonvolatile diluent oil to the carbonated admixture,

(D) heating the admixture to remove substantially all of the volatile materials, and

(E) blowing the admixture with carbon dioxide to convert substantially all of the remaining calcium oxide or calcium hydroxide to calcium carbonate.

While not necessary to my process, nonvolatile diluent oil can be present in the admixture of step (A). Preferably, at least about half of the amount present in the final product is added after the first carbonation step (i.e., step Stated more specifically, the present invention is directed to a process for preparing large batches (e.g. at least 100 gallons) of a stable dispersion of calcium carbonate in a nonvolatile diluent oil, wherein the process comprises: (A) forming an admixture of (1) about 5 to about 30 parts by weight of an oilsoluble dispersing agent (2) about to about 50 parts by weight of a volatile hydrocarbon solvent (3) about 5 to about 30 parts by weight of methanol '(4) at least about 0.25 parts of a nonvolatile diluent oil, and (5) calcium oxide or calcium hydroxide in an amount to provide an acetic base number of at least 50 in the final product, (B) treating the admixture of step (A) with an amount of carbon dioxide which is above 0.75 and less than 0.95

mole, per mole of overbasing calcium, while the admixture is at a temperature not exceeding about 35 C., (C) adding to the admixture of step (B) an amount of nonvolatile diluent oil suflicient to bring the total of nonvolatile diluent oil to about to about 85 parts per 100 parts of the combined weight of oil-soluble dispersing agent and nonvolatile diluent oil,

'(D) heating the admixture to remove substantially all of the volatile materials, and

(E) blowing the admixture of step (D) with carbon dioxide to convert substantially all of the remaining calcium oxide or calcium hydroxide to calcium carbonate.

be above 0.75 and less than 0.95 mole per mole of overbasing calcium. More suitably, the amount of carbon dioxide is from about 0.78 to about 0.90 mole per mole of overbasing calcium, while preferably the amount of carbon dioxide, on the same basis, is from about 0.80 to about DETAILED DESCRIPTION Materials Used The oil-soluble dispersing agents used in my process include only the oil-soluble sulfonic acids. The term oilsoluble sulfonic acids, as used herein, refers to those materials wherein the hydrocarbon portion of the molecule has a molecular weight in the range of about 300 to about 'sulfonic acid is believed to be well understood, since it is amply described in the literature. The term synthetic sulfonic acids refers to those materials which are prepared by sulfonation of hydrocarbon feedstocks which are prepared synthetically. The synthetic sulfonic acids can be derived from either alkyl or alkaryl hydrocarbons. In addition, they can be derived from hydrocarbons having cycloalkyl (i.e., naphthenic) groups in the side chains attached to the benzene ring. The alkyl groups in the alkyl hydrocarbons can be straight or branched chain. The aryl radical of the alkaryl hydrocarbons can'be-phenyl, ethyl: phenyl, tolyl, xylyl, or naphthyl, but preferably isphieriyll An example of a hydrocarbon feedstock whic'li'has'been particularly useful in preparing synthetic sulfo'nic acids is a material known as postdodecylbenzene. Postdodecylbenzene is a bottoms products of the manufacture of dodecylbenzene. The alkyl groups ofpostdodecylbenzene are branched chain. Postdodecylbenzene cons'ists'of monoalkylbenzenes and dialkylbenzenes in the approximate mole ratio of 2:3 and has typical properties as follows:

Specific gravity at 38 c 0.8649 Average molecular weight 385 Percent sulfonatable I 88 A.S.T.M. D-158 Engler: v i I.B.P., F. "Q 6 47 5, F. 682 50, F. 715 90, F. 760 95, F. 775 F.B.P. F. 779 Refractive Index at 23 C. .1.4900 Viscosity at 10 C., centistokes .L 2800 20- C., centistokes 2180 40 C., centistokes 78 C., centistokes l8 Aniline point, C. 69 Pour Point, F. -25

An example of another hydrocarbon feedstock which is particularly useful in preparing synthetic sulfonic acids is a material referred to as dimer alkylate. 'Dimer alkylate? consists primarily of aryl compounds having one long branched-chain alkyl group. Briefly described, dimer alkylate is prepared by the following steps:

( 1) dimerization of a suitable feedstock, such as cat poly gasoline; (2) alkylation of an aromatic hydrocarbon with the dimerformed in step 1).

Preferably, the dimerization step uses a Friedel-Craft's alkylation sludge as the catalyst. This process and the resulting product are described in U.S. Pat. No.- 3,410,925. An example of still another. hydrocarbon feedstock is a material similar to dimer alkylatejbut' which has'one substantially straight long-chain alkyl group..

An example of yet another hydrocarbo'nfeedstock which is particularly useful for preparing synthetic sulfonic acids which can be used in my invention is a material which is the bottoms product resulting from the preparation of a biodegradable detergent alkylate (i.e., a substantially straight-chain monoalkylbenzene),jjland which is referred to as NAB Bottoms. NAB Bottoms are predominantly di-n-alkyl aromatic hydrocarbon wherein the alkyl groups contain from 8 to 18 carbon atoms. They are distinguished primarily from thepreceding sulfonation feedstocks in thatthey are both straight chain and contain a large amount of di-substituted material. The process ofpreparing thesejma- 'terials and the resulting product are described in application Ser. No. 521,794, filed Jan. 20, 1966 and,now

abandoned and having the same assignee as the present application. Another process of preparing a di-n-alkar yl product is described in application Ser. No. 529,284,.filed Feb. 23, 1966 and now abandoned, and having the same assignee as the present application. I In order to make my disclosure even more' complete, applications Ser. Nos. 521,794 and 529,284 and US. Pat. No. 3,410,925 are made a part of this disclosure.

In addition to the-sulfonic acids derived from the foregoing-described hydrocarbon feedstock, examples of other suitable sulfonic acids include the following: monoand polywax-substituted naphthalene sulfonic acid, dinonyl naphthalene sulfonic acid, diphenyl ether sulfonic acid, naphthalene'disulfide sulfonic acid, dicetyl thianthrene sulfonic acid, dilauryl beta-naphthol sulfonic acid, dicapryl nitronaphthalene sulfonic acid, unsaturated paraffin. wax sulfonic acid, hydroxysubstituted parafiin wax sulfonic, acid, tetraamylene sulfonic acid, monoand poly-chlorosubstituted paraifin wax sulfonic acid, nitrosoparafiin wax sulfonic acid; cycle-aliphatic sulfonic acid such as lauryl-cyclohexyl sulfonic acid, monoand polyw'ax-substituted cyclohexyl' sulfonic acid, and the like.

In addition to thesulfo'nicac'ids described in the foregoing, mixtures of these sulfonic acids can be used.

Usual y, thecommercially available sulfonic acids are not 100 percent 'sulfonic'acid 'but'contain some nonvolatile diluent'oil. The amount of nonvolatile diluent oil can range from about 5v to about 90 parts by weight per 100 parts of sulfonic acid. Expressed on the same basis, more suitably the' amount of nonvolatile diluent oil is from about to about 60 parts by weight. Preferably, on the same basis, the amount of nonvolatile diluent oil is from about to about 50 parts by weight.

A wide variety of nonvolatile diluent oils are suitable since the principal requisite is that they act as a solvent for the dispersing agent. The term nonvolatile diluent oil as used herein refers to both the unsulfonated feedstock and to intentionally addedtmaterials. In some cases these intentionally added materials are added during the sulfonation of the feedstock and are therefore concurrently'presen't'in the sulfonic acid starting material. These oils have a-boiling' point in excess of about 200 C. Examples of suitable nonvolatile diluent oils, other than the unsulfo'nated hydrocarbons, include mineral lubricating oils obtained by any of the'conventional refining procedures; liquid synthetic lubricating-oils, such as polymers of propylene, polyoxyalkylenes, polyoxypropylene, dicarboxylic acid esters,-'such as esters of adipic and azelaic acids with alcohols: such as butyl, 2-ethylhexyl and dodecyl alcohols; hydrocarbon synthetic lubricating oils, such as dim-C "alkylbenzenes, alkyl-substituted tetrahydr'onaphthalenes -diphenylalkanes, and mixtures there- 'of; vegetable oils, such ascorn oil, cotton seed oil, and caster oil; animal oils, such as lard oil and sperm oil. The more suitable nonvolatile diluent oils are the mineral lubricating and the synthetic hydrocarbon lubricating oils, as defined'hereinbefore. The preferred nonvolatile diluent oils are the mineral lubricating oils.

' Suitable volatile solventsfinclude both aromatic and aliphatic hydrocarbon solvents having a boiling point belowabout 150C; Examples of suitable solvents include .benzene, toluene, xylene, heptane, hexane, and petroleum .naphtha. The preferredsolvents are the aliphatic hydrocarbons, e.g., hexane or petroleum naphtha.

My invention is restrictedxto methanol as the alcohol since: neither ethanol nor isopropanol works in my process, although many of the prior art processes teach that C C or C -C alkanols can be used to prepare hyperbasic dispersions-In addition,--it--is of interest that thealkoxy ethanols (e.g., methoxyethanol) do not work 1n my processsince theprior art teaches that alkoxy ethanols can bc u sed itowp'r'epare. hyperba'sic dispersions.

Either calcium oxide or calcium hydroxide can be used in my processfln some instances when the oil-soluble dispersing agent is'an acid and/ or contains a small amount material as commercially feasible since less unreacted material will have to be removed by filtration.

Amounts of Materials The relative amounts of materials used, except the nonvolatile diluent oil, are shown below in tabular form.

*This amount is characterized further in that it is sutficient to provide an acetic base number (measure of overbaslng calcium) in the product of at least 50, more suitably at least 100, and preferably at least 200.

The amount of nonvolatile diluent oil present in the initial admixture is 'better understood when considered in connection with the sulfonic acids, as described hereinbefore, and with that amount of nonvolatile diluent oil used in the process, as described hereinafter. Actually, it is not required that any nonvolatile diluent oil be present in the initial admixture. From a practical viewpoint there is usually at least 0.25, more usually at least 0.50, part of nonvolatile diluent oil present in the initial admixture. The amount of nonvolatile diluent oil used in my process suitably is that amount required to provide from about 20 to parts per parts of the combined weight of dispersing agent and nonvolatile diluent oil in the final product. Expressed on the same basis preferably the amount of nonvolatile diluent oil is from about 40 to about 60 parts.

The amount of nonvolatile diluent oil added to the admixture after carbonation is dependent on the amount of nonvolatile diluent oil present in conjunction with the dispersing agent. When the dispersing agent is a natural sulfonic acid or sulfonate, little, if any, nonvolatile diluent oil is added. When the dispersing agent is a sulfonic acid or sulfonate prepared from a synthetic hydrocarbon, usually addition of a nonvolatile diluent oil is necessary in order to provide a final product having sufiicient fluidity.

"Process Conditions In conducting the process of my invention an admixture is first formed of the oil-soluble dispersingagent, volatile hydrocarbon solvent, methanol and calcium oxide or calcium hydroxide. While the entire amount of nonvolatile diluent oil can be added to the initial admixture, preferably this is not done. Preferably, the only nonvolatile diluent oil present in the initial admixture is that which is concurrently present in the dispersing agent. In this connection, it is my hypothesis that the presence of a minimum amount of nonvolatile diluent oil in the initial admixture provides better phase mixing between the dispersing agent and the methanol.

Even though this may be redundant, let me summarize the statements concerning the nonvolatilediluentoil:

(1) Preferably, the only nonvolatile diluent oil present in the initial admixture is that present concurrently with the dispersing agent.

(2) Since oil-soluble dispersing agents contain some nonvolatile diluent oil there will usually be at least a small -amount present.

(3), Natural sulfonic acids contain usually more nonvolatile diluent oil than sulfonic acids derived from synthetic hydrocarbon feedstocks.

(4) When nonvolatile diluent oil is added during the process preferably at least one-half is added after carbonation; The admixture is then carbonated, preferably by blowing with CO while-the temperature of the admixture does not exceed about 35 C. Carbonation of the admixture can be begun when the temperature is as low as 10 C. In order to prevent the admixture from becoming viscous and thereby having poor contact with the CO it is important that the temperature be at least about 22 C. by the time at least one-fourth, preferably at least onethird, of the amount of CO required in this first carbona- 8 In order to disclose the nature of the present invention still more clearly, the following examples, both illustrative and comparative, will be given. It is to be understood that the invention is not to be limited to the specific Conditions or details set forth in these examples except insofar as tion step is added. such limitations are speclfied 1n the appended claims.

In order to insure consistent results it is often desirable i EX LE 1 that this first carbonation step be conducted at a tempera- M ture in the range of from about 22 to about 35 0., pref- ThlS example provides a serles of runs-"of 12-l1ter erably from about 23 to about 30 C. batches which show that the CO /Ca who is very impor- The carbonation step is an important feature of my tant. v process. First, the carbonation is conducted at a rela- Materials Used v a I tively slow rate. For example, thebtime of carbogiatiog Sulfonic lad d1 0 should be In the range of from a out 0.25 to a out ca(OH)2 (commercia1 hydrated lime) do 471 hours, preferably in the range of from about 1 to about 15 Methanol 750 3 hours. Within the ranges previously stated, the time T of carbonation varies with the size of the batch with g i g q zfifg i zi fi i g gk sggg i larger batches requiring longer time periods. Secondly, viscosit of SSU 1 0 r g g the amount of carbon dioxide added at this stage is very y 3 g ams r important. An insuflicient amount of carbon dioxide regg i g g s p ep12 g g gfiglults in a low utilization of lime (i.e., amount Converted benzene from dimeriz gd dodecene'and 30 percent of stripped to final product). The unreacted lime increases the solids s. which contain substantialfflmounts of content of the final product and results in poor filtration. gg fig ffigg 33$ f;fi fi gfgfi ggfigfl gig gggggfgr herein The An excessive amount of carbon dioxide decreases the sta sfillfmiic a --;----D f bility of the product As a result. instead of a fluid H2 i fi j'i i fif??i f fliii iiijfiii: 221% dispersion, the product is grease-like. In order to use Residual sulfuric acid do 0.05 t correct amount of carbon dioride the amount of Sithifiilffiiffl fiffi iliiiiiinapgi.0233 overbasing calcium present in the admixture must be Sulfonicacidity meq./g 0.59s known and the amount of carbon dioxide added must be Nonvolatlles measured. Procedure With the foregolng conditlons 1n mlnd a suitable amount Th f H 1 d of carbon dioxide is above 0.75 mole and less than 0.95 l i 'R was mole per mole of overbasing calcium. More suitably, the e Omc so utlon .a(OH)2 an t g amount of carbon dioxide is from about 0.78 to about l l were added to a lzhter creased flask The re- 0.90 mole per mole of overbasing calcium while prefer- 35 mammg methanpl was added h i t was'cooled ably the amount of carbon dioxide, on the same basis, is to the carbonanon tempelauire Indicated m Table'l from about 080 to about 035 mole low. The amount of Co indlcated in Table I wasadded Following the carbonation step it is often desirable, in while maintaining the temperature atthat indicated in the order to provide better contact of the various reactants, i fi 9 fi g z g q over a two'hour to heat the admixture to reflux temperature and maintain 40 peno 8 par la y car imate a mlxture heated. to the temperature at reflux for a short time reflux temperature (-50 C.) over a-4d-m1nute period At this point the additional nonvolatile diluent oil, as and hleld at reflux temperture 15 F The l required is added to the admixture The volatile mate pale 011 was added, following which the volatile materials O rials are then substantially removed by heating the adwere y geatmg T temperature of 150 mixture, as for example to a pot temperature of about a g 252 3 While q 150 C. When large batches of product are prepared (e.g., was out C t e a mlxture was blown wlth CO2 12 liters and above), it usually requires three to four 0 P any a( )zpresem to caco3 and to remcive hours to remove substantially all of the nonvolatile residual solvents and water. The samples forthe filtration terials. and BS. and W. tests were removed before settling of the The admixture is then blown with carbon dioxide, gen- 93? occurred M d d erally while it is maintained at the final heating tempera- T b1 es an pro not esults are Shown m ture. This blowing with carbon dioxide at this point d th serves to convert substantially all of the remaining CaO e a a m e a lste ta e Show the followmg' or Ca(OH) to calcium carbonate. In addition, the blow- (1) Use of a CO /Ca mole ratio of 0.75 and below reing with carbon dioxide serves to remove traces of vola- 5 sults in low utilization of Ca'(OH) and a product which tile materials, such as solvent and water. does not filter. r

Generally, the product is filtered or centrifuged to re- (2) Use of a CO /Ca mole ratio of 0.95 and above remove suspended materials, i.e., unreacted lime and impurisults in a thick, grease-like product-not a fluid'disperties 1n the lime added initially. sion. Y

TABLE I Moles CO2 Carbona- Utilizaper mole tion temtion of B.S. and W.,1 overbasing peratpre, Product, Oa(OH)2, ml. ppt./100 Acetic Ca 0. grams percent g. product base No. Filtration 0.70 20-25 I 2,027 80.5 .2 Y 0. 24m 2,041 91.5 1.5 id oi men 0.80 295:1 2,050 r 90.7 r 1.9 295 Sminutes. r 0.35 29i1 2,055 3 90.0 1.0 293-- Do. 3-22 33:: I... d 1 r -erouc-are' 1. 1 29-25 Both runs became very mill y and viscous izv i li sim i-solid material on the sides of reaction vessel at'70 C. during distillation of solvent 1 The precipitate was obtained by dilutin rams of the roduct to 200 ml. 1 e I and centrifuging 20 minutes at 1,500 r.p.m. g g p 1 r tom 79mm nhexape' 1 On clarified product.

2 The filtrations were run on grams of product slurrid with 2'7 (wt.) L HYFLO and filtered h a HYFLO precoat. The filtrations were carried out using a heate d coarse sintered glass iunnel'(600 111%.

The time recorded indicates the time required to *HYFLO 1s a diatomaceous earth filter aid.

produce a dry condition on the topof the filter cake.

9 EXAMPLE 2 This example shows that use of a carbonation temperature above the suitable range not in excess of- 35 C'.,

.while using the preferred range of Ca, does not produce a satisfactory product.

100 grams and was very ditfi'cult to filter. It would barely filter even with constant scraping.

EXAMPLE 3 This example illustrates the preparation of a pilot plant batch of the product prepared by the process of my in- This material was a hexane solution of a sulfonic acid prepared by the sulfonatiou of NAB Bottoms, as described previously herein. The solution had the following analysis:

anol were added to the reaction vessel and the admixturecooled to 30 C. The admixture was then carbonated by blowing CO through a sparger at the bottom of the reaction vessel over a period of 106 minutes while maintaining the temperature within the range of 25-30 C. Over a 30 minute period the reaction mass was heated to reflux -50 C.), and held at reflux temperature for five minutes. Then the 80 pole oil was added, following which the volatile materials were removed by heating to a pot temperature of 150 C. over a three-hour period. The

a product was CO stripped for one hour at 150 C.

The amount of product recovered was 331.5 pounds which after filtration had the following analysis:

Base No. (acetic) 283%.

Percent active (calcium sulfonate) 28.26%.

Viscosity at 210 F. 180.5 S.S.U. (38.46 cs.)

The product was bright and fluid.

' EXAMPLE 4 This example illustrates the preparation of a plant batch of the product prepared by the process of my invention.

Percen Hexane 56.3 Water 0.5 Sulfonic acid (molecular weight 438) 24.7 Nonvolatile diluent oil and unsulfonated hydrocarbon 1 .0 2 This was a hexane solution of a sulfonic acid prepared y 'the sulfonation of a mono-l0ng chain (Can-24) alkylhenzeues.

The solution had the following analysis Percent Hexane 65.05 Water 0.35 Sulfonic acid (molecular weight 514) 21.2 Nonvolatile diluent oil and unsulfonated hydrocarbon 3.4

Procedure The procedure used was as follows: The sulfonic acids, Ca(OH) and one-half of the meth- 10 Materials Used 'Lbs. .Sulfonic acid solution 9576 Methanol 2 772 CaO (amount required to neutralizethe acid) 160 Ca( OH) (Mississippi lime-grease maker grade)" 2050 Mineral lubricating oil (viscosity of 75 S. S.U. at

F.) 3085 C0 (0.775 mole Co /mole overbasing Ca) 890 1 The sulfonic acid solution was a hexane solution of mixed sulfonic acids corresponding to that used in Example 3. The sulfonic acid solution had the following composition:

Lbs.

Sulfonic acid 2633.4 Water 52.7 Unsulfonated alkylate and oil 909.7 Volatile solvents (hexane) 5980.2

Total 9576.0

Procedure The procedure used was as follows.

The sulfonic acid solution, methanol and calcium oxide were added first to the reaction vessel. The Ca(OH) was then added and the admixture cooled to 23 C. The carbon dioxide was added over a period of three hours six minutes at a rate of about 5 pounds per minute. During the carbonation step the maximum temperature was 30.5 C. The admixture Was then heated to remove a substantial portion of volatile solvents and when the temperature reached 53 C. the mineral lubricating oil was added. The resulting admixture was heated to a product temperature of C. to remove substantially all of the solvents. The product was blown with CO for one hour at a rate of 5 pounds CO per minute while the temperature of the admixture was held within the range of 150 C. The product was further stripped for one hour and 45 minutes with a plant inert gas (having the following composition: 12% C0 1% CO, and 87% N to remove the last traces of solvent.

Prior to filtrating the product had the following properties:

Acetic base number 301 Flash Point, F. 385 B. S. & W., percent 3.6

1 See footnote 1 below.

After filtering, the product had the following properties:

Acetic base number 292 Percent active (calcium sulfonate) 30.8 B. S. & W. Trace Viscosity, cs. at 210 F. 48.1-

In this example the B.S. & W. was the percent precipitate based on the product when 50 ml. product is diluted with 50 ml. hexane and centrifuged 20 minutes at 1500 r.p.m.

The products of this example were filtered using a plant filtering press using 3.7% diatomaceous earth filter and a yield of 850 gallons of product was obtained in 35-40 minutes with very little pressure buildup, thereby indicating excellent filtering properties for the product.

EXAMPLE 5 This example is comparative and shows that ethanol (absolute) and isopropyl do not work in the process of my invention. Twelve liter preparations made using a mole ratio CO overbased Ca of approximately 0.80. The details of the runs are shown below.

RUN A Materials Used v Sulfonic acid soultion* gram's 2180 Isopropanol (Mallinckrodt Co.-analytical reagent grade 0.2% H 0 maximum ml.. 750 Ca'OH (commercial grade) "grams" 471 100 pale oil do 486 C0 (101.8 liters) do.. 199.9

*The Sulfonic acid solution was the 'same as used in Example 1.

Procedure mixture to maintain the temperature at 30:1" C. rather than cooling which was used when methanol was used. During the CO blowing a wet test meter was used to measure the amount of CO not reacted, which was 63.0 liters of CO In addition, during the heating to reflux temperature 5.8 liters of additional CO were released.

The product weighed 1935 grams and a B.S. & W. test, using 50 grams of product and 50 ml. of hexane, gave a result of 40% (amount of material precipitated).

The results of this run are summarized in Table II.

RUN B Material Used Sulfonic acid solution* grams 2180 Ethyl alcohol-absolute (U.S.P.-N.F., U.S. Industrial Chemicals Co.) ml 750 Commercial hydrated lime grams 471 100 pale oil do 486 C (104.8 liters) do 205.8

*The sulfonic acid solution was the same as used in Run A and Example 1.

Procedure The procedure used was substantially the same as in Example 1. The CO was added over a period of 115 minutes. During the CO blowing it was again necessary, as in Run A, to heat the admixture in order to maintain the temperature at 30:1 C.

A wet test meter was used to measure the amount of CO not reacted, which amounted to 84.0 liters of CO During the heating to reflux 9.05 additional liters of CO were released.

The product weighed 909 grams and a B.S. & W. test using the same procedure as in Run A gave a result of 45%. The results of this run are summarized in Table H. In addition for purposes of comparison the third column of Table II contains the results of a substantially similar run using methanol as the alcohol.

1 0.80 mole ratio of CO /overbasing Ca=200.4 g.

EXAMPLE 6 A series of runs were made which show the eflect of beginning the carbonation at a temperature as low as 10 C. Three l-liter and one 12-liter runs were made. The sulfonic acid used in all of the runs was prepared from a monoand dialkylbenzene mixture. The sulfonic acid had the following analysis:

Total acidity, meq./g. 1.30 Sulfonic acid acidity, meq./g. 1.25 Combining weight 455 Water, percent wt. 0.10 Nonvolatiles, percent 98.7

Run number Amounts of materials A-C D Sulfom'c acid, g 101.3 1,013 Hexane, g 129. 2 1, 292 Methanol, ml 75.0 750 CaO, g. (for neutralization) 3. 7 37 Ca(OH) g. (grease-maker lime) 43. 6 436 Mineral lubricating oil, 500 S.S.U. at F., g 442 Procedure-Run A The sulfonic acid and hexane were added to the reaction flask. Then the methanol, CaO, and Ca(OH) were added to the flask. Using an ice bath the admixture was cooled to 10 C. The admixture was then blown with CO for 13 minutes while maintaining the temperature in the range of l0-12 C. (The total amount of CO was sutficient to provide 0.85 moles per mole of overbasing Ca.) It was observed during the CO addition that the admixture became very-viscous after about one-half the CO was added and some CO was lost (as measured by a wet test meter) presumably due to poor contact between the CO and reaction mass.

Upon completion of the CO blowing the admixture was heated to reflux temperature, maintained at this temperature for 30 minutes, whereupon the mineral lubricating oil was added. The admixturewas heated to C. to remove volatile materials, and then stripped with CO gas for 15 minutes at 150-160 C. The yield of product was 202.3 grams. The product was hazy and fluid. Fiftytwo grams of product were removed for B.S. & W. tests and 150 grams were filtered using Hyflo diatomaceous earth filter aid.

The process conditions and product analyses are summarized in Table III which follows.

ProcedureRun B The procedure was the same as in Run A except that the temperature during carbonation was 15.5-17 C. Again, the admixture became very viscous after about one-half the CO was added.

The yield of product was 202.5 grams. The product was bright and fluid.

The process conditions and product analyses are summarized in Table III which follows.

Procedure-Run C The procedure was the same as in Run A except that the temperature during carbonation was in the range of 23.3 to 24.4 C. The admixture was very fluid during the carbonation and substantially no C0 (0.02 liter) was given ofl. The yield of product, which was fluid and hazy, was 203.1 grams.

The process conditions and product analyses are summarized in Table III which follows.

Procedure-Run D The procedure was the same as in Runs A-C except for the following differences. As indicated previously, this run used an amount 10 times that in Runs A-C. Accordingly, a 12-liter reaction flask was used. Also, the carbonation time was 131 minutes as compared to 13 minutes for the Runs A-C. 'Ihe carbonation was conducted over a temperature range of 10 to 32 C. The carbonation was started at 10 C. After about one-fourth of the 00 had been added the temperature was 21 C. AfterC one-half the CO was added, the temperature was 30 Although 4 liters of CO were lost during the blowing, some of the loss may have been mechanical since the glass frit tube may not have been sufficiently below the surface of the admixture.

The admixture was very fluid during the CO blowing.

The yield of product, which was very fluid and only slightly hazy, was 2067 g.

13 The process conditionsandgproduct analyses are summarized in Table lll wh i ch tollov B C D ,;;Size.liter. 1: 1 1 '12 C'arbdnation tfn'pg" C 10-12 16. 5-17 23. 3-24. 4 10-32 Cog/Ca, mole ratio 0.85 0.85 0. 85 0. 85 CO: ofl during canlznalite 0. 6 1. 0. 02 4. 0 CO1 added, liter ll. 24 ll. 24 11. 24 112. 4 Product BS and W., percent 1 2. 2.4 2. 2 0. 9 Filter time, minutes. 9 4. 8 4. 25 Percent Hyfiog. 2 4 2 2 Filtered product base No I ,300 298 301 301 Percent B.S. and W 0. 005 0. 005 0. 00 0. 03

X Unfiltered.

I The filter time is the time to obtain a dry cake when 150 g. of the product slurried with the filter aid at 160 C., is filtered through a 7 cm. diameter heated Biichner funnel.

While it is believed to be inherent from the description of the test procedures as stated previously herein, the BS. &' W. test is a measure of the precipitate produced on diluting the product with a hydrocarbon solvent (e.g. hexane) and centrifuging the resulting solution. It is an indication of the amount of the sediment (or precipitate) which would result when the product is used as an additive in lubricating oils.

Having thus described the invention by providing specific examples thereof, it is to be understood that no undue limitations or restrictions are to be drawn by reason thereof arid that many variations and modifications are within the scope of the invention.

The invention having thus been described, what is claimed and desired to be secured by Letters Patent is:

1. A process for preparing a stable dispersion of calcium carbonate in a nonvolatile diluent oil wherein the process comprises:

(A) forming an admixture of (1) about 5 to about 30 parts by weight of an oil soluble dispersing agent selected from the group consisting of oil soluble sulfonic acids and the calcium salts thereof,

(2) about 10 to about 50 parts by weight of a volatile hydrocarbon solvent having a boiling point below about 150 C.,

(3) about 5 to about 30 parts by weight methanol,

(4) at least about 0.25 parts by weight of a nonvolatile diluent oil having a boiling point of above about 200 C, and

(5) from about 1 to about 25 parts by weight of "calcium oxide, calicum hydroxide or mixtures (thereof, said amount being characterized fur- :ther in that it is sufilcient to provide an acetic base number of at least 50 in the final product,

(B) treating the admixture of step (A) with an amount of carbon dioxide which is above 0.75 and less than 0.95; mole, per mole of overbasing calcium, while the admixture is at a temperature not exceeding about 35 C.,

(C) adding to the admixture of step (B) an amount of nonvolatile diluent oil sufiicient to bring the total of the nonvolatile diluent oil to about 20 to about 85 parts per 100 parts of the combined weight of the oil soluble dispersing agent and nonvolatile diluent 011,.

(D) heating the admixture to remove substantially all of the volatile materials, and

(E) blowing the admixture of step (D) with carbon dioxide to convert substantially all of the remaining calcium oxide or calcium hydroxide to calcium carbonate.

2. The process of Claim 1 wherein in step (B) the temperature is at least about 22 C. by the time at least one-fourth of the carbon dioxide requirement is added.

3. The process of Claim 2 wherein the nonvolatile diluent oil is selected from the group consisting of mineral lubricating oils and synthetic hydrocarbon lubricating 14 10118, such as di-n-C alkylbenzenes, alkyl-subs-tituted tetrahydronaphthalenes, diphenylalkanes and mixtures thereof.

4. The process of Claim 3 wherein the amount of carbon dioxide in step (B) is from about 0.78 to about 0.90 mole per mole of overbasing calcium.

5. The process of Claim 4 wherein the amount of nonvolatile diluent oil added in step (C) is suflicient to bring the total amount of nonvolatile diluent oil to about 40 to about 60 parts per 100 parts of the combined weight of oil soluble dispersing agent and nonvolatile diluent oil.

6. The process of Claim 5 wherein the hydrocarbon solvent of step (A) is as aliphatic hydrocarbon.

7. The process of Claim 6 wherein the nonvolatile diluent oil is a mineral lubricating oil.

8. The process of Claim 7 wherein the entire amount of the carbon dioxide requirement of step (B) is added while maintaining the temperature of the admixture in the range of from about 22 to about 35 C.

9. A process for preparing a stable dispersion of calcium carbonate in a nonvolatile diluent oil, said stable dispersion being characterized as having an acetic base number of at least 100, wherein the process comprises:

(A) forming an admixture of (1) about 10 to about 20 parts of an oil soluble dispersing agent selected from the group consisting of oil soluble sulfonic acids and the calcium salts thereof,

(2) about 20 to about 35 parts of a volatile hydrocarbon solvent having a boiling point below about 150 C.,

(3) about 10 to about 20 parts methanol,

(4) at least about 0.5 parts of a nonvolatile diluent oil having a boiling point above about 200 C., and

(5) about 10 to about 20 parts calcium oxide, calcium hydroxide or mixtures thereof, said amount being sulficient to provide an acetic base number of at least 100 in the final product,

(B) treating the admixture of step (A) with from about 0.78 to about 0.90 mole of carbon dioxide, per mole of overbasing calcium, while the admixture is at a temperature not exceeding about 35 C.,

(C) adding to the admixture of step (B) an amount of nonvolatile diluent oil sufficient to bring the total of the nonvolatile diluent oil to about 20 to about parts per parts of the combined weight of the oil soluble dispersing agent,

(D) heating the admixture to remove substantially all of the volatile materials, and

(E) blowing the admixture of step (D) with carbon dioxide to convert substantially all of the remaining calcium oxide or calcium hydroxide to calcium carbonate.

10. The process of Claim 9 wherein in step (B) the temperature is at least about 22 C. by the time at least one-fourth of the carbon dioxide requirement is added.

11. The process of Claim 10 wherein the nonvolatile diluent oil is selected from the group consisting of mineral lubricating oils and synthetic hydrocarbon lubricating oils, such as di-n-C alkyl-bcnzenes, alkyl-substituted tetrahydronaphthalenes, diphenylalkanes and mixtures thereof.

12. The process of Claim 11 wherein the amount of non-volatile diluent oil added in step (C) is sufficient to bring the total amount of nonvolatile diluent oil to about 40 to about 60 parts per 100 parts of the combined weight oil oil soluble dispersing agent and nonvolatile diluent o1 13. The process of Claim 12 wherein the hydrocarbon solvent of step (A) is an aliphatic hydrocarbon.

14. The process of Claim 13 wherein the nonvolatile diluent oil is a mineral lubricating oil.

15. The process of Claim 14 wherein the oil soluble dispersing agent is an oil soluble sulfonic acid.

16. The process of Claim 15 wherein the oil soluble dispersing agent is an oil soluble sulfonic acid prepared by sulfonation of a synthetic hydrocarbon selected from the group consisting of mono-alkaryl hydrocarbons, dialkaryl hydrocarbons and mixtures thereof.

17. The process of Claim 16 wherein the amount of calcium oxide, calcium hydroxide or mixtures thereof used in step (A) (5) is sufiicient to provide an acetic base number of at least 200 in the final product.

18. The process of Claim 15 wherein the entire amount of the carbon dioxide requirement of step (B) is added while maintaining the temperature of the admixture in the range of from about 22 to about 35 C.

10 I. VAUGHN, AssistantExaminer Z16 References 'Cited s UNITED STATESPATENTS 3,014,866 12/1961 Fermi,- 2,865,956 12/1958 Ellis et'al. 3,488,284 1/ 1970 1. Le- Suerettal. J 3,470,097 9/ 19 69 I avigne et al.-

DANIEL E. WYMAlillrimary Examiner v v p C1. X.R. 252-33 7;; V 

